1988 Silverado Turn Signal

I have 1988 Chevy Silverado where the turn signals do not work. The lights do not come on or is there an flashing inside. I am guessing it may be a burned out bulb because we checked the fuses and the flasher. However, I cannot figure out how to get to the turn signal lights. Any suggestions? I can see the lights for the head lights.

My 89' had sheet metal screws holding the turn signals in place. The taillights are assed by opening the tailgate. on yje tailiht fender section there are 2 sheet metal screws,i think they are torx screws. You have to remove the whole rear taillight assembly to get a the lights.